13.罗马数字转整数

    public int romanToInt(String s) {
        int[] store = {1000,900,500,400,100,90,50,40,10,9,5,4,1};
        String[] strs = {"M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I"};
        HashMap<String,Integer>  maps= new HashMap<>();
        for (int a = 0; a < store.length; a++) {
            maps.put(strs[a],store[a]);
        }
        int result = 0;
        for (int i = 0; i < s.length(); ) {
            if (i+1 < s.length() && maps.containsKey(s.substring(i,i+2)) ) {
                result += maps.get(s.substring(i,i+2));
                i+=2;
            }else{
                result += maps.get(s.substring(i,i+1));
                i++;
            }
 
        }
        return  result;
    }